size of 2d array in c++

To determine the size of a 2D array in C++, you need to consider the number of rows and columns in the array. The size of a 2D array is calculated by multiplying the number of rows by the number of columns.

Here's an example code snippet that demonstrates how to find the size of a 2D array in C++:

#include <iostream>

int main() {
    int arr[3][4]; // 2D array with 3 rows and 4 columns

    int rows = sizeof(arr) / sizeof(arr[0]); // calculate the number of rows
    int cols = sizeof(arr[0]) / sizeof(arr[0][0]); // calculate the number of columns

    std::cout << "Number of rows: " << rows << std::endl;
    std::cout << "Number of columns: " << cols << std::endl;

    return 0;
}

In this example, we have declared a 2D array arr with 3 rows and 4 columns.

To calculate the number of rows, we divide the total size of the array (sizeof(arr)) by the size of the first row (sizeof(arr[0])). This gives us the number of elements in a row.

Similarly, to calculate the number of columns, we divide the size of the first row (sizeof(arr[0])) by the size of an individual element (sizeof(arr[0][0])). This gives us the number of elements in a column.

The output of this code will be:

Number of rows: 3
Number of columns: 4

This tells us that the 2D array has 3 rows and 4 columns.